Metallurgical study on chips obtained by high speed machining of a Ti–6 wt.%Al–4 wt.%V alloy

A metallurgical analysis on chips obtained by high speed machining of a Ti–6wt.%Al–4wt.%V alloy has been performed to provide a better understanding of chip formation mechanisms. For this purpose, X-ray diffraction, energy dispersive X-ray analysis, scanning electron microscopy and electron backscattering technique were employed. The titanium β phase was observed in all chips for any tested cutting speeds. No evidence of phase transformation was found in the shear bands. Microscopical observations are in agreement with the catastrophic thermoplastic shear model for saw-tooth chip formation, instead of the periodic crack initiation one.